Electromagnetic mechanism.



H. PIERSON. ELEGTROMAGNETIG MECHANISM. APPLICATION FILED 00:1". s, 1906.

969,493. Patented Sept. 6,1910.

2 SHEETS-SHEET 1'.

75 I Q mum WITNESSES:

ATTORNEY H. PIBRSON.

ELECTROMAGNETIC MECHANISM.

APPLICATION FILED OCT. a, 1906.

Patented Sept. 6,1910

2 SHEETS-SHEET 2.

[211$ bars INVENTOR ATTORNEY HENRY PIERSQN, OF MANCHESTER, ENGLAND, ASSiIGNOR- T0 WESTINGHOUSE ELEC- TRIC & MANUFACTURING COMPANY, A

GORPORATIQN OF PENNSYLVANIA.

ELECTROMAGNETIC MECHANISM.

To all whom it may concern:

Be it known that I, HENRY Pmnsorz, a

subject of the King of Great Britain, and

a. resident of Manchester, in the county of Lancaster, England, have invented a new v ter member due to a change in the flow of current in the circuit or circuits is utilized to give a visible or audible signal or to actuate a circuit-breaker or perform a like function either directly by mechanical means or indirectly by closing or opening a relay circuit.

According to this invention, an iron yoke is employed having three inwardly projecting pole pieces in two of which a i'nagnetic flux is induced by a coil or conductor carrying either the whole 0 a shunted portion of the current in the main circuit while the remaining pole piece has a flux induced therein by a coil connected in shunt across the main circui or across the terminals of an auxiliary source of current such as a battery. A movable armature located in the fields produced by thesctiuxes and is mechanically or electrically restrained in one direction against a stop but free to move in the opposite direction.

One form of the invention is illustrated in the a :companying drawings in which Figure 1 is a side elevation of the mechanism applied to a circuit-brealier of a well lrnown type, a part of which. with switch board panel. is also shown. Fig. 3 is a rear elevation ot the electro-niagnetic mechanism shown in Fig. 1.

Referringto the said figures of the drawing, the device comprises a magnetizable yolte or frame constructed in two parts 1. secured t'o g'ethci by bolts 3 so that the same can be mounted upon or suspended from one of the leading-in studs of a circuit breaker 5, preferably at the rear of the switch board 6. The portion 1 of the yoke Specification of Letters Patent.

Application filed October 3, 1908.

being I h 1 -ture pivot ior cooperation with the Patented Sept. 13, 1910. Serial No. 387,328.

or frame has three inwardly projecting pole pieces 7, 8, 9 having curved polar faces, the pole pieces 7 and 8 being located near together with the leading-in stud 4 between them and opposite to the third pole piece 9, which latter is furnished with a shunt winding 10. Within the fields produced by said pole pieces is pivoted a magnetizable armature 11 that is held normally in a predetermined position against a stop 12 by a spring 13, a wei hted lever or other mechanical restraining means, a stop 12 being provided to limit the movement of the armature in the other direction. The force exerted by the restraining means may be adjusted to limit the movement or the armature and to any the conditions under which the mechanism is to operate, a screw being shown applied to the spring 13 for this purpose.

Normally, the direction of the flux induced in the poles 7 and 8 by the main can rentfiowing through the stud 4 is such that, if combined with the Hun produced in the pole piece 9 by the shunt winding 10, it tends to maintain the armature 11 in the position in which itis mechanically held, the armature being shaped that the reluctance of the ma gnetic circuit is a minimum. This condition of the flux is indicated in the several parts by the arrows. G11 the other hand. when the direction of the flux produced by the main current is reversed by a reversal of said errent, said main current flux will combine with the shunt flux at the pole piece where previously they were opposed, and will oppose at the pole piece 8, where previously they were combined, with. the result that the armature 11 turnsi'ipon its pivot and mechanically operates the trip gear of the circuitdu'c. lcer; in this inst; me, through the medium of what may be 1. .her an underload or an overload aiachnient ll: of the circuibbre .wr, an arm .or cam .15 urcd to an e. 'ension 16 of the armaattachment The lore action will result when only :1- ve i5. current flows in reverse i Lion, the shunt coil being normally en In th c ot a hea reversal of t and no tation or slight eXeitathe shunt coil, owing to drop of busbar pressur t c 'l'luX produced by the cur rent in the main circuit: is sufiicient to cause the armature 11 to turn against its restraining means, viz. the spring 13, until the reluctance at both of the pole pieces 7 and 8 becomes equalized, the angular movement depending upon the relative values of the air-gaps between the armature and the pole pieces and also upon the shape of the armature. With a reasonable overload current in the normal direction and excitation of the shunt coil, the device will not operate, but with an abnormal overload of dangerous proportions accompanied by a fall of busbar pressure and consequent weakening of the current flowing in the shunt coil. 10 (such as may be caused by a dead shortcircuit in the system) the device will operate in exactly the same manner as in the case of heavy reversal accompanied by a fall of bus-bar pressure, the field produced by the main current simply being changed in direction.

It will be understood that the operation hereinbefore described obtains when a plurality of dynamo-electric machines an operated in parallel. Under such conditions, a reversal of current in the main circuit of the breaker, with which any one of the machines is equipped, will not be attended by a reversal of current in the shunt circuit which includes the coil 10 because the busbar pressure will be maintained by the other generators of the set.

Obviously, the details of construction may be variously modified. For instance, the main current pole pieces 7 and 8 may be excited -byindependent windings carrying either the whole or a shunted portion of the current'in the main circuit. The device is furthermore capable of general application and its use is not restricted to operating a switch or for breaking circuits as shown, this being merely one use to which the device may be put.

I claim as my invention:

1. In an electromagnetic apparatus, the combination with a stationary magnetizable member having two side-by-side pole pieces, an opposite pole piece, means for producing a magnetic flux through said side-by-side pole pieces and a separate means for pro ducing a flux through said opposite pole piece, of a movable, magnet-izable member that is subjected to said magnetic fluxes and is movable thereby when that through'the side-by-side pole pieces is reversed or greatly exceeds that through the opposite pole piece. 2. The combination with a magnetizable frame having two side-by-side pole pieces and one opposite pole piece, a series-com nected conductorfor magnetizing the sideby-side pole pieces and a shunt-connected conductor for magnetizing the opposite pole piece, of a pivoted armature having its ends adjacent to the respective pole pieces, and

yielding means for normally holding said armature in a position corresponding to normal currents in the magnetizing concircuits, and a yielding restraining means that holds the armature in a given position when the magnetizing currents are normal in amount and direction and is overcome when one of the currents becomes abnormal in direction or excessively abnormal in amount.

4-. The combination with a magnetizablc member having two magnetizing conductors the magnetic circuits of which intersect at two points, of a movable armature that projects into the points of intersection of the magnetic fluxes and is held in one position when the magnetizing currents are normal. in direction and amount but is moved to other position when one of the currents is reversed in direction or becomes excessive in amount.

5. The combinationwith a stationary magnetizable member having two separately energized magnetizing conductors the mag netic circuits of which intersect at two points, of a movablearmature that is trav ersed by the flux produced by one of said conductors and one end of which projects into the said intersection points, whereby the said armature is moved from one position to another when the current in one of the conductors is reversed in direction or is greatly.increased in amount as compared with that in the other.

6. The combination with a magnetizable yoke or frame having a pair of inwardlyprojecting pole pieces at one side and a single inwardly-projecting pole piece at the opposite side, a conductor. for. oppositely magnetizing the pair of pole pieces and a separately excited conductor for magnet?- ing the single pole piece, of an armature pivotally mounted to bridge the space between the pair of pole pieces and the single pole piece, and restraining means for the armature that is overcome when the normal direction of one of the magnetizing currents is reversed or when said current greatly exceeds its normal amount.

7 .,The combination with a stationary ma'gnetizable member havinga pair of pole pieces at one side and a single pole pie at the op osite side the face of which spans an arc of approximately the same length as that spanned by the pair of pole pieces, a series conductor for oppositely magnetizing the pair of pole pieces and a shunt conductor for magnetizing the single pole piece, of an armature pivotally mounted between said pole 91% e seems e s, iimiti .g' stops for seicl ermature, and s. yielding means for normally holding the armature in one of its extreme pnsitions.

The eembinzitien with a stationary magnetizable member having two aresliepecl adjacent polar faces and a single are-shaped polar face oppesite thereto, a singie conducter for producing a, magnetic flux between Sit-id etijacent polar faces and a separately excited conductor for producing amagnetic flux between said epposite polar face and each of said adjacent faces, of an armature that is pix e-tally meunte i restrained t0 cenduct the flux pretlucecl tie separately excited eenducter and. the sition sf which depends upon the direc- 13] J]: E the between, the adjacent polar er the relative ameunts 01 the two 9. The combination with a stationary magnetizable member having a. pair 0f adjacent polar faces separated by a gap and oppositelyvpolarized by a single circuit, and? single polar face opposite said adjacent faces and a separately excited conductor fer pmdueing a flux between said single polar face and each of said pair of polar faces, of a. pivoted armature having a limited range of movement and yielding means that tends to hold said armature in one of its extreme positions.

In testimony whereof, I have hereunto subscribed my name this 17thrday of September, 1906.

HENRY PIERSON. Viitnesses:

W. J. P. ORTON, s Vi'imiin F. JONES. 

